1. Field of the Invention
The present invention relates to a color photographic light-sensitive material having improved color reproducibility and, more particularly, it is concerned with a color photographic light-sensitive material having excellent color reproducibility improved by adroitly using an interlayer color correction (ICC) uncolored coupler.
2. Description of the Prior Art
Usually, a multi-layered color photographic light-sensitive material comprises a blue-sensitive emulsion layer unit (BL) which contains a yellow coupler and which is mainly sensitive to blue light (substantially shorter than about 500 nm in wave length), a green-sensitive emulsion layer unit (GL) which contains a magenta coupler and which is mainly sensitive to green light (substantially about 500 to 600 nm in wavelength), and a red-sensitive emulsion layer (RL) which contains a cyan coupler and which is mainly sensitive to red light (substantially longer than about 590 nm in wavelength). Each of these light-sensitive emulsion layer units must perform its own independent function required for good color reproduction. For this purpose, an intermediate layer (ML), a filter layer (FL) for filtering out light including ultraviolet light, an anti-halation layer (AHL), and a protective layer (PL) can further be provided. In addition, each light-sensitive emulsion layer unit must independently contain a coupler capable of providing the unit with a suitable spectral sensitivity distribution in a suitable wavelength region and capable of providing images having suitable spectral absorption. However, color photographic light-sensitive materials thus far obtained still possess numerous defects.
A first defect thereof in connection with color reproduction lies in the spectral absorption characteristics of the colored images obtained from the couplers used. That is, sufficient light absorption is not attained in a specific wavelength region and, in addition, the light absorption extends too widely into other undesired wavelength regions. This defect results in a narrow color reproduction region, a shear in hue and, particularly, a reduction in saturation.
A second defect lies in that the image development of a specific light-sensitive emulsion layer can cause the coloration of a coupler contained in a neighboring light-sensitive layer.
A third defect lies in that a sensitizing dye used for the spectral sensitization of a specific light-sensitive emulsion layer diffuses into a neighboring light-sensitive emulsion layer and sensitizes the neighboring light-sensitive layer to impart an unsuitable spectral sensitization distribution.
As methods for removing these defects, the provision of an ML or FL or the incorporation in an ML or FL of a reducing compound such as a hydroquinone derivative (e.g., 2,5-di-t-octylhydroquinone, 2-(1-phenyltetrazol-5-ylthio)-5-n-octadecylthiohydroquinone, etc.), a phenol derivative, ascorbic acid derivative; a scavenger for oxidized color developing agent (primary amine armatic compound); a compound capable of colorlessly coupling; a coupler capable of forming a diffusible dye; an agent for preventing sensitizing dyes or couplers from diffusing, such as fine silver halide grains, colloidal silica, Hectite or a like clay; an anionic, nonionic or cationic surface active agent; a cationic hydrophilic synthetic polymer; a hydrophilic synthetic polymer having hydroquinone derivative; a polymer latex, and the like; have been suggested. However, these improvements are not yet satisfactory.
Another type of method for improving "color separation" lies in the introduction of an element which is positively provided with a "color correcting" function. One such method is a method of using a colored coupler provided with an auto-masking function, for example, as disclosed in, e.g., U.S. Pat. Nos. 2,455,170; 2,449,966; 2,600,788; 2,428,054; 3,148,062; 2,983,608; British Pat. No. 1,044,788, Japanese Pat. application No. 45971/73. However, this method has the defect that the non-image light-struck area is also strongly colored. Therefore, this colored coupler cannot be applied to positive color light-sensitive materials. In addition, the use of the colored coupler tends to increase fog, which deteriorates the graininess or granularity of the color image formed.
Another such method is a method of using a so-called "DIR coupler". The term DIR coupler as used herein means those couplers specified in C. R. Barr, J. R. Thirtle and P. W. Vitlum, Photographic Science and Engineering, vol. 13, pp. 74 - 80 (1969) and ibid, pp. 214 - 217 (1969), or in U.S. Pat. No. 3,227,554. Usually, a DIR coupler is known to bring about interlayer effects. However, it has the defect that the development of the emulsion layer containing the coupler is delayed and the gradation (gamma), maximum color density (Dmax) and effective sensitivity are deteriorated. When a DIR coupler, particularly, a DIR coupler whose coupling position is substituted with an arylthio group or a hetero ring thio group as described in, e.g., U.S. Pat. No. 3,227,554, is added to an emulsion layer of a silver halide of a fine grain size, there is the defect that no or almost no interlayer color-correcting effect is obtained. Therefore, in connection with color reproduction, it is of technical interest to remove these defects.
Thirdly, a method of using a substantially fogged emulsion or a direct positive emulsion in an ML, a method of further using a coupler in combination, a method of using an internally fogged emulsion or an internal latent image-type emulsion, a method of employing Luckey effect, or the like are known. However, these methods of using silver halide emulsions entail a reduction in sharpness due to the light-scattering effect of the grains contained therein on exposure, difficulties in controlling photographic properties of the emulsion itself, photographic side effects, and the like.
Fourthly, a method of controlling the halide composition of the silver halide emulsion itself which is used in each light-sensitive emulsion unit, a method of controlling the interlayer distribution of an antifogging agent, a stabilizer and a restrainer, and the like are known. However, the color-correcting effect obtained by controlling these factors are not satisfactory.
In addition, there are factors involved in development processing. However, color-correcting effects by controlling these factors are not satisfactory, either.